"I do not have rice for sushi."
Translation:У меня нет риса для суши.
«Нет» is used in the following cases:
- When answering a yes/no question: «Вы говори́те по-узбе́кски?» — «Нет». ('Do you speak Uzbek?' 'No, I don't.')
- When talking about absence of something, we use «нет» + Genitive case form of the thing missing. This is usually translated 'there's no' or 'there're no': «Во всём до́ме нет све́та» ('There's no electricity in the whole house.' Literally: in whole house there-is-no light). In this construction «нет» may be replaced with «не́ту» in colloquial speech: «Во всём го́роде нету магазина комиксов» (There's not [a single] comics shop in the whole town. Literally: In whole town there-is-no shop of-comics)
- As a particular case of the previous construction, when a preposition «у» is used to indicate possession, we translate it with «don't have», «have no»: «У меня́ нет соба́ки» (I don't have a dog. Literally: at me there-is-no dog)
In all the other cases, we use «не». Notably:
- When negating most verbs: «Я не зна́ю» (I don't know)
- When negating adjectives (it's spelled as one word then): «несве́жий хлеб» (non-fresh bread, i.e. stale bread)
- In sentences of the type «X is not Y»: «Я не ве́дьма» 'I'm not [a] witch'.
There is one more use, a short negation of a statement with the omission of the "real" verb or other predicate that would carry the meaning:
- Мы инженеры, а они нет. = We are engineers, and they aren't.
- Мария спит, а я нет. = Maria is asleep (sleeping) and I am not.
- Анна любит Тома, а он её нет. = Anna loves Tom, yet he does not love her.
You probably remembered the use of на in на завтрак / на обед / на ужин / на десерт. This is mostly used with these meals. It does not fit here.
- there is another, fairly narrow meaning of на that sort of corresponds to English "for". It means a quantity of resource to be depleted in making/buying/achieving something—e.g., "money for (hiring) another employee" , "concrete enough for 2 floors".
За + Accusative corresponds to English "for" in the following cases:
- support ("He is for Liberal Democrats", "Are you for or against me?)
- exchange ("I bought this for $20", "Thanks for your help")
- replacement, to a degree (in English replacing "instead" with "for" might cause confusion)